Ultrasound diagnostic apparatus

Abstract

An ultrasound diagnostic apparatus capable of obtaining a high-quality ultrasound image while suppressing the temperature rise in an ultrasound probe. The ultrasound probe includes receive amplification units including amplifiers for amplifying reception signals outputted from a transducer array and a power supply unit for supplying bias current to the amplifiers. The power supply unit changes the bias current it supplies to the amplifiers according to the depth of a reflection position of ultrasonic echo.

1 . An ultrasound diagnostic apparatus comprising
 an ultrasound probe including
 a transducer array for transmitting ultrasonic waves and receiving ultrasonic echo reflected by a subject to output reception signals corresponding to received ultrasonic waves, 
 signal processors each including a receive amplification unit having an amplifier for amplifying reception signals outputted by the transducer array to process the reception signals; and 
 a power supply unit for supplying bias current to the amplifier and 
   a diagnostic apparatus body for producing an ultrasound image corresponding to the reception signals processed by the signal processors of the ultrasound probe,   wherein the power supply unit changes a current value of the bias current supplied to the amplifier according to a depth of a reflection position of the ultrasonic echo.   
     
     
         2 . The ultrasound diagnostic apparatus according to  claim 1 , wherein the power supply unit increases the bias current supplied to the amplifier as the depth of a reflection position of the ultrasonic echo increases. 
     
     
         3 . The ultrasound diagnostic apparatus according to  claim 1 , wherein the receive amplification unit includes a plurality of amplifiers and amplifies the reception signals through multiple stages, and wherein the power supply unit changes a current value of a bias current supplied to a first-stage amplifier according to the depth of a reflection position of the ultrasonic echo. 
     
     
         4 . The ultrasound diagnostic apparatus according to  claim 1 , wherein the receive amplification unit includes a low-noise amplifier, and wherein the power supply unit changes a current value of a bias current supplied to the low-noise amplifier according to the depth of a reflection position of the ultrasonic echo. 
     
     
         5 . The ultrasound diagnostic apparatus according to  claim 1 ,
 wherein the ultrasound probe includes an analog/digital converter for converting the reception signals into digital signals, and   wherein the analog/digital converter changes a sampling rate used in converting the reception signals into digital signals according to the depth of a reflection position of the ultrasonic echo.   
     
     
         6 . The ultrasound diagnostic apparatus according to  claim 5 , wherein the analog/digital converter lowers the sampling rate used in converting the reception signals into digital signals as the depth of a reflection position of the ultrasonic echo increases. 
     
     
         7 . The ultrasound diagnostic apparatus according to  claim 6 , wherein the analog/digital converter changes the sampling rate used in converting the reception signals into digital signals according to time elapsed as from transmission of the ultrasonic wave. 
     
     
         8 . The ultrasound diagnostic apparatus according to  claim 1 , wherein the ultrasound probe transmits and receives the reception signals to and from the diagnostic apparatus body via wireless communication. 
     
     
         9 . The ultrasound diagnostic apparatus according to  claim 1 , wherein the power supply unit changes the current value of a bias current supplied to the amplifier and/or the low-noise amplifier according to the time elapsed as from transmission of the ultrasonic wave.